Drill sharpener



Nov. 17, 1931. E. CROFT DRILL' SHARPENER Filed Oct. 8, 1928 5 Sheets-Shea Nov. 17, 1931. L. E. CROFT 1,832,186

DRILL SHARPENER Filed Oct. 8, 1928 5 sne'ets sheet 2 Fild Oct. 8, 1928 5 Sheets-Shee s Nov. 17, 1931. L. E. CROFT 1,832,186

DRILL SHARPENER Filed Oct. 8, 1928 5 Sheets-Shee 5 Patented Nov. 17, 1931 arr FF-icsf LORENZO n. cnorr, or DENVER, COLORADO,=ASSIGNOR 'ro GARDNER-DENVER coivr- .PANY, on DENVER, COLORADO, a CORPORATION or DELAWARE DRILL snanrnnnn Application file'd October 8, 1928. Serial No. 311,227.

The present invention relates to metal I working machines and particularly of the type commercially known as drill Sharpeners.

The object is to provide a compact sturdy apparatus, in which different pressures may be brought upon the die members for forging or holding purposes and to provide novel means for distributing motive fluid to eii'ect a well-known sequence of operations.

A preferred embodiment of the invention is illustrated in the acompanying drawings, wherein V- Figure l is a side elevation of the'apparatus with parts shown in section.

Figure 2 is a sectional view of the line 2-2 of Figure 1.

Figure 3 is a top plan view of the machine.

Figure 4 is a detail horizontal sectional view on the line 4-401 Figure 1.

Figure 5 is a detail vertical sectional View diagrammatic in its character in order to illustrate the various passageways.

Figures 6 and 7 are corresponding sectional views showing the controlling apparatus in different positions.

In the embodiment disclosed, a base is employed, consisting of a lower section 8 having a chamber 9 that constitutes a reservoir for motive fluid. It is supplied from any suitable source by a pipe 10 connected; to a,

nipple 11 formed on one side of the sectionS. A vent cock 12 may be provided on one side of the section,.and a cleanout opening 13 formed in the bottom of said section is normally closed by a cap plate 14. In the upper portion of the section 8 is formed a vertical piston chamber 15 having a bottom wall 16 that constitutes a partition between said piston chamber 15 and the motive fluid reservoir 9.

. 19 with a vertical piston chamber 20 and the crating dies 28. This block 27 is fixed to verbottom 19 has a centrally disposed upstanding tubular guideway- 21 extending into said piston chamber 20. i

A head plate 22 is located on the sectionlS j and constitutes a closure for the upper'endof the piston chamber 20. This head plate and the sections 8 and 18 aresecured together by side bolts 23 passing through vertical ribs support or holder for metal working or hold- 24in 'said'sections and engaged with the ing dies 26. It will be understood that this may be of various characters and for the purpose of this invention need not be detailed.

Over said mounting or block 25, which is thus fixed, is another block 27 that is mOvabletoward and from the block 25 and carries coopa tically movablecarrier rods or bolts 29 that slidably pass through the block 25 and head plate 22 and have their lower ends fixed to a piston 30 that reciprocates in the piston chamber 20. Preferably" the bolts 29, as shown, constitute tie bolts between the piston 30 and the block 27 by passing directly through both, and interposed betweensaid piston 30and block 27 are spacing sleeves 31 surrounding the bolts. Thepiston 30 has an integral depending centrally disposed piston rod 32 slidably mounted'in the guide 21, and preferably provided with suitable packing rings therein, as shown at 33. The lower end of the piston rod 32 is reduced in diameter, as shown at 34,'and mountedon said reduced portion 34 is a sleeve 35 carying a piston 36 abutted against a shoulder 37 formed; at the upper end of the reduced portion 34. The

' piston 36 operates in the piston chamber 15,

and the'piston 36 and sleeve 35 are held'in place by a nut 38 threaded upon the lower end of the piston rod and abutting'the lower end of the'sleeve 35. The lower end of said sleeve 35 operates in the cylinder 17 and its lower end together with the nut 38 constitute a piston whose lower surface is exposed to the pressure of" the motive fluid in the reservoir chamber 9.

Formed upon one side ofthe base section 18 is an enlargement 39, constituting a valve casing and provided with a valve chamber 40. A supply passageway 41 leads from the reservoir chamber 9 in the base section 8 upwardly. through such base section 8 and surmounting section 18 and opens into an annular groove 42 formed in the chamber 40. At one side of said groove 42 is a second internal annular groove 43 from which leads a distributing passageway 44 that' opens into the upper end of the upper piston chamber and above the piston therein. At a place further removed from the supply groove 42 is formed a third internal annular groove 45 from which leads a distributing passageway .46 that extends downwardly through the wall of the upper section 18 and opens into the lower piston chamber 15, above the piston 36. A controlling valve, preferably of the plunger type, is located in the valve chamber40 and consists of .a pair of spaced heads 47 and 48 connected by a reduced portion 49 forming a chamber 50 that is in constant communication with the supply passageway 41 and groove 4:2. The inner head 47 constitutes means for controlling comdie member.

munication between the supply passageway .41 and the passageways 44 and 46. The outer head 48 constitutes a supporting guide and is provided with outstanding ears 51 that are connected by a link 52 with an actuating lever 53 suitably fulcrumed as shown at 54 on a bracket 55 carried by the enlargement 39. The other end of this lever is provided with a hand grip 56.

With the construction as thus far described, it will be evident that when the head 47 is interposed between the groove 42 and groove 48, communication between the passageways 41 and 44-46 is cut off. When the valve is moved inwardly, however, the

passageway 44 is first brought into communication with the supply passageway 41 and motive fluid will thus pass through said passageway 44 into the upper end of the piston chamber 20 and operate upon the upper surface of the piston 30. As the pistons and upper-head block 27 are normally lifted by the pressure against the lower piston 3538, the motive fluid acting on the piston 30, which has a muchlarger area than the lowermost piston,'will move the pistons and connected head block 27 downwardly into coactive relation with the'lower block 25. By moving the piston valve back and forth, obviously motive fluid canbe alternately admitted to and cut off-from the passageway 44, and when cut ofi, said passageway 44 is open to atmosphere through the rear open end 57 of the valve chamber 40' so that the fluid can exhaust from the piston chamber 20, permitting the lower piston 35-38 to. react and raise the movable Thus a forging operation of a hammering nature may be effected. If the valve is given a greater movement toward the open end 57 of the valve chamber, obviously the motive fluid is first given access to the passageway 44 and thus operates on the upper piston 30, but thereafter the other passageway 46 will be opened so that motive fluid will find its way into the upper end of the piston chamber 15, and as both passageways 44 and 46 are now simultaneously open, the fluid will operate simultaneously on both pistons 30 and 36. The piston 30 has moved the die member 27 downwardly and there fore the piston 36 now cooperates therewith, in giving a much greater holding effect. This holding effect is obtained primarily for dollying purposes as in the sharpening of rock drills.

Therefore as shown in Figure 1, the head plate is provided with an outstanding bracket 58 on which is mounted a fluid operated dollying hammer 59. The piston 60 of;-

this hammer operates on a dolly 61 that cooperates with one of the sets of holding dies 26 28 in a manner well understood. Motive fluid to the dollying hammer 59 is supplied by a hose 62 and this hose is in communication of said valve is so positioned, however, that 1 it is not struck by the lever53 until after the head 47 of the valve has open communication between the supply passageway 41'and the groove 45 (see Figure 5).

The operation of this part of the mechanism is as follows. Vhen the valve head 47 has'moved to a position to permit the supply of fluid to the groove 45 and consequently to the passageway 46 and the lower piston chamber 15, fluid will also enter the inlet end of the passageway 63, but cannot flow to the dollying hammer 59 because the valve 66 is closed (see Figure 7). A further movement of the valve 53, however, will cause the same to open said valve 66 as shown in Figure 5, and thus motive fluid will be supplied to the dollying hammer when both pistons 30 and 36'are cooperatively holding a tool in position to be operated by said hammer. 'Upon a reverse movement of the lever 53 motive 5 fluid is first cut off from the dollying hammer 59 by the closing of the valve 66. Then the.

.motive fluid is cut oil from the lower piston chamber 15 and said chamber above the piston is opened to atmosphere through the port 57. Thirdly motive fluid is cut off from the upper piston chamber 20 and said chamber above the-piston is also opened to atmosphere through the port 57 The pressure thus being relieved on the two cooperating pistons 30 and 36, the smaller return piston '38 can operate to raise these two pistons and the upper die member 27.

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be ap parent to those skilled in the art without further description and it will be understood that various changes in the size, shape, proportion and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

hat I claim, is:

1. In an apparatus of the charaacter set forth. the combination with relatively movable die members, of a fluid operated motor for relatively moving the same and including a plurality of coacting plstons, a fluid operated dollying mechanism, a valve cham ber, means for supplying motive fluid to the valve chamber, a distributing passageway leading from the valve chamber to one of the pistons, a second passageway leading-from the valve chamber to the other piston, a third passageway leading from the valve chamber to the dollying mechanism, a valve movable to a position to deliver motive fluid to the first passageway only and to a position to simultaneously open the second and third passageways to the flow of motive fluid therethrough, and a second valve controlling the third passageway.

2. In an apparatus of the character set forth, the combination with relatively movable die members, of a fluid operated motor for relatively moving the same and including a plurality of coacting pistons, a fluid operated dollying mechanism, a valve chamber, means for supplying motive fluid to the valve chamber, a distributing passageway leading from the valve chamber to one of the pistons, a second passageway leading from the valve chamber to the other piston, a third passageway leading from the valve chamber to the dollying mechanism, a valve movable to a position to deliver motive fluid to the first passageway only and to a position to tributing passageways leading from the valve chamber at spaced points to the piston chambers on the same. side of the pistons therein, a motive fluid supply passageway leading to the dollying hammer, a valve for opening the distributing passageways to the piston chambers successively and permitting them to be both open at the same time to effect a cooperative action of the pistons on the movable die member, means for operating the valve, and a valve controlling the passage of-motive fluid to the dollying hammer, and operable to open position by the first valve operating means when the two distributing passageways are both open.

4L. In apparatus of the character set forth, the combination with a base member having a plurality of piston chambers and also having a fixed die member on its upper end, a plurality of pistons in the piston chambers having a central connection between them, a movable die member over the fixed die member and coacting therewith, and spaced piston rods located on opposite sides of the central connection and engaged with one of the pistons, said rods passing through the fixed die and connected to the movable die, and means for directing motive fluid against one of the pistons and to both two pistons simultaneously.

In testimony whereof, I afiix my signature.

LORENZO E. CROFT.

cause the second and third passageways to i be open at the same time, a second valve controlling the third passageway, and means for operating the first valve and causing the sec ond valve to be opened after the second and third passageways are open.

3. In an apparatus of the character set forth, the combination with a base containing a plurality of piston chambers and a fixed die member thereon, of pistons in the respective piston chambers, a movable die member over the fixed member coacting therewith and connected to said pistons, a fluid operated dollying hammer for operating on work clamped by the die members, a valve chamber, a motive fluid supply passageway opening thereinto, separate dis- 

